Negative voltage generation for computer memory

Abstract

Techniques for negative voltage generation for a computer memory are described herein. An aspect includes enabling a first negative word line voltage (VWL) clock generator. Another aspect includes providing, by the first VWL clock generator, based on a clock signal, a first pump clock signal to a first VWL pump, and a second pump clock signal to a second VWL pump. Another aspect includes generating a VWL based on the first VWL pump and the second VWL pump, wherein the VWL is provided to a word line driver of a computer memory module. Another aspect includes comparing the VWL to a VWL reference voltage. Another aspect includes, based on the VWL being below the VWL reference voltage, disabling the first VWL clock generator, wherein the first VWL pump and the second VWL pump are disabled based on disabling the first VWL clock generator.

What is claimed is: 
     
       1. A method comprising:
 enabling a first negative word line voltage (VWL) clock generator; 
 providing by the first VWL clock generator, based on a clock signal, a first pump clock signal to a first VWL pump, and a second pump clock signal to a second VWL pump, wherein the first pump clock signal is out of phase with the second pump clock signal; 
 generating a VWL based on the first VWL pump and the second VWL pump, wherein the VWL is provided to a word line driver of a computer memory module; 
 comparing the VWL to a VWL reference voltage; and 
 based on the VWL being below the VWL reference voltage, disabling the first VWL clock generator, wherein the first VWL pump and the second VWL pump are disabled based on disabling the first VWL clock generator. 
 
     
     
       2. The method of  claim 1 , the method comprising:
 enabling a second VWL clock generator; 
 providing by the second VWL clock generator, based on the clock signal, a third pump clock signal to a third VWL pump, and a fourth pump clock signal to a fourth VWL pump, wherein the third pump clock signal is out of phase with the fourth pump clock signal; 
 generating the VWL based on the first VWL pump, the second VWL pump, the third VWL pump, and the fourth VWL pump; 
 comparing VWL to the VWL reference voltage; and 
 based on the VWL being below the VWL reference voltage, disabling the second VWL clock generator, wherein the third VWL pump and the fourth VWL pump are disabled based on disabling the second VWL clock generator. 
 
     
     
       3. The method of  claim 1 , wherein the first VWL pump is connected to a supply voltage VDD and to a voltage bit line high (VBLH), wherein VBLH is from about 0.7 volts (V) to about 0.9 V. 
     
     
       4. The method of  claim 1 , wherein the first VWL pump comprises a wire capacitor that is connected in parallel with a low threshold voltage (LVT) n-type metal oxide semiconductor (NMOS) device, wherein a capacitance of the wire capacitor and LVT NMOS device is charged based on the first pump clock signal. 
     
     
       5. The method of  claim 1 , wherein comparing the VWL to the VWL reference voltage is performed by a VWL comparator, the VWL comparator comprising:
 input circuitry configured to receive the VWL reference voltage; 
 a resistor ladder configured to receive the VWL; 
 a comparator configured to compare the VWL to the VWL reference voltage; and 
 a stack inverter configured to output an enable signal to the first VWL clock generator based on the comparison. 
 
     
     
       6. The method of  claim 5 , the method further comprising:
 receiving a plurality of control bits, each of the plurality of control bits comprising a direct current (DC) signal, by the VWL comparator, such that the plurality of control bits configure the VWL comparator based on projected process, voltage, and temperature (PVT) conditions in the computer memory module during operation of the computer memory module by bypassing one or more resistors in the input circuitry or the resistor ladder; 
 wherein the input circuitry is configured to raise the VWL reference voltage; and 
 wherein the resistor ladder is configured to lower the VWL. 
 
     
     
       7. The method of  claim 1 , wherein the computer memory module comprises an embedded dynamic access memory (eDRAM) memory module that is embedded in a processor chip. 
     
     
       8. A system comprising a circuit configured to:
 enable a first negative word line voltage (VWL) clock generator; 
 provide, by the first VWL clock generator, based on a clock signal, a first pump clock signal to a first VWL pump, and a second pump clock signal to a second VWL pump, wherein the first pump clock signal is out of phase with the second pump clock signal; 
 generate a VWL based on the first VWL pump and the second VWL pump, wherein the VWL is provided to a word line driver of a computer memory module; 
 compare the VWL to a VWL reference voltage; and 
 based on the VWL being below the VWL reference voltage, disable the first VWL clock generator, wherein the first VWL pump and the second VWL pump are disabled based on disabling the first VWL clock generator. 
 
     
     
       9. The system of  claim 8 , the circuit configured to:
 enable a second VWL clock generator; 
 provide, by the second VWL clock generator, based on the clock signal, a third pump clock signal to a third VWL pump, and a fourth pump clock signal to a fourth VWL pump, by the second VWL clock generator, wherein the third pump clock signal is out of phase with the fourth pump clock signal; 
 generate the VWL based on the first VWL pump, the second VWL pump, the third VWL pump, and the fourth VWL pump; 
 compare the VWL to the VWL reference voltage; and 
 based on the VWL being below the VWL reference voltage, disable the second VWL clock generator, wherein the third VWL pump and the fourth VWL pump are disabled based on disabling the second VWL clock generator. 
 
     
     
       10. The system of  claim 8 , wherein the first VWL pump is connected to a supply voltage VDD and to a voltage bit line high (VBLH), wherein VBLH is from about 0.7 volts (V) to about 0.9 V. 
     
     
       11. The system of  claim 8 , wherein the first VWL pump comprises a wire capacitor that is connected in parallel with a low threshold voltage (LVT) n-type metal oxide semiconductor (NMOS) device, wherein a capacitance of the wire capacitor and LVT NMOS device is charged based on the first pump clock signal. 
     
     
       12. The system of  claim 8 , wherein comparing VWL to the VWL reference voltage is performed by a VWL comparator, the VWL comparator comprising:
 input circuitry configured to receive the VWL reference voltage; 
 a resistor ladder configured to receive the VWL 
 a comparator configured to compare the VWL to the VWL reference voltage; and 
 a stack inverter configured to output an enable signal to the first VWL clock generator based on the comparison. 
 
     
     
       13. The system of  claim 12 , the circuit configured to:
 receive a plurality of control bits, each of the plurality of control bits comprising a direct current (DC) signal, by the VWL comparator, such that the plurality of control bits configure the VWL comparator based on projected process, voltage, and temperature (PVT) conditions in the computer memory module during operation of the computer memory module by bypassing one or more resistors in the input circuitry or the resistor ladder; 
 wherein the input circuitry is configured to raise the VWL reference voltage; and 
 wherein the resistor ladder is configured to lower the VWL. 
 
     
     
       14. The system of  claim 8 , wherein the computer memory module comprises an embedded dynamic access memory (eDRAM) memory module that is embedded in a processor chip. 
     
     
       15. A device, comprising logic configured to:
 enable a first negative word line voltage (VWL) clock generator; 
 provide, by the first VWL clock generator, based on a clock signal, a first pump clock signal to a first VWL pump, and a second pump clock signal to a second VWL pump, wherein the first pump clock signal is out of phase with the second pump clock signal; 
 generate a VWL based on the first VWL pump and the second VWL pump, wherein the VWL is provided to a word line driver of a computer memory module; 
 compare the VWL to a VWL reference voltage; and 
 based on the VWL being below the VWL reference voltage, disable the first VWL clock generator, wherein the first VWL pump and the second VWL pump are disabled based on disabling the first VWL clock generator. 
 
     
     
       16. The device of  claim 15 , the logic configured to:
 enable a second VWL clock generator; 
 provide, by the second VWL clock generator, based on the clock signal, a third pump clock signal to a third VWL pump, and a fourth pump clock signal to a fourth VWL pump, wherein the third pump clock signal is out of phase with the fourth pump clock signal; 
 generate the VWL based on the first VWL pump, the second VWL pump, the third VWL pump, and the fourth VWL pump; 
 compare the VWL to the VWL reference voltage; and 
 based on the VWL being below the VWL reference voltage, disable the second VWL clock generator, wherein the third VWL pump and the fourth VWL pump are disabled based on disabling the second VWL clock generator. 
 
     
     
       17. The device of  claim 15 , wherein the first VWL pump is connected to a supply voltage VDD and to a voltage bit line high (VBLH), wherein VBLH is from about 0.7 volts (V) to about 0.9 V. 
     
     
       18. The device of  claim 15 , wherein the first VWL pump comprises a wire capacitor that is connected in parallel with a low threshold voltage (LVT) n-type metal oxide semiconductor (NMOS) device, wherein a capacitance of the wire capacitor and LVT NMOS device is charged based on the first pump clock signal. 
     
     
       19. The device of  claim 15 , wherein comparing the VWL to the VWL reference voltage is performed by a VWL comparator, the VWL comparator comprising:
 input circuitry configured to receive the VWL reference voltage; 
 a resistor ladder configured to receive the VWL 
 a comparator configured to compare the VWL to the VWL reference voltage; and 
 a stack inverter configured to output an enable signal to the first VWL clock generator based on the comparison. 
 
     
     
       20. The device of  claim 19 , the logic configured to:
 receive a plurality of control bits, each of the plurality of control bits comprising a direct current (DC) signal, by the VWL comparator, such that the plurality of control bits configure the VWL comparator based on projected process, voltage, and temperature (PVT) conditions in the computer memory module during operation of the computer memory module by bypassing one or more resistors in the input circuitry or the resistor ladder; 
 wherein the input circuitry is configured to raise the VWL reference voltage; and 
 wherein the resistor ladder is configured to lower the VWL.